Saugus was founded in 1888 when the Southern Pacific Railroad built a line out to Ventura. It joined with the mainline here. One part of the original Saugus still remains, Saugus Cafe.
In 1938, after using this alignment for about a year, this section of US 6 was bypassed. It was rerouted onto Sierra Highway. US 99 used this alignment from 1926-1930. US 99 followed Magic Mountain Parkway to its post-1930 alignment at The Old Road. All of the bridges that remained along this alignment, except the Newhall Creek Bridge, dated to that era. Sadly, all those old bridges are now gone.